58390-19-5Relevant articles and documents
Continuous N-alkylation reactions of amino alcohols using γ-Al2O3 and supercritical CO2: Unexpected formation of cyclic ureas and urethanes by reaction with CO2
Streng, Emilia S.,Lee, Darren S.,George, Michael W.,Poliakoff, Martyn
, p. 329 - 337 (2017/03/15)
The use of γ-Al2O3 as a heterogeneous catalyst in scCO2 has been successfully applied to the amination of alcohols for the synthesis of N-alkylated heterocycles. The optimal reaction conditions (temperature and substrate flow rate) were determined using an automated self-optimising reactor, resulting in moderate to high yields of the target products. Carrying out the reaction in scCO2 was shown to be beneficial, as higher yields were obtained in the presence of CO2 than in its absence. A surprising discovery is that, in addition to cyclic amines, cyclic ureas and urethanes could be synthesised by incorporation of CO2 from the supercritical solvent into the product.
Structural and Mechanistic Effects on the Rates of Ring-Opening Reactions in the 5-16-Membered-Ring Region
Cerichelli, Giorgio,Illuminati, Gabriello,Lillocci, Claudio
, p. 3952 - 3957 (2007/10/02)
Partial rate coefficients have been determined for the reaction of cyclic dimethylammonium ions with sodium methoxide in the 7-16-membered-ring region.Three second-order parallel reactions take place and lead to exocyclic demethylation (A), ring-opening substitution (B), and ring-opening olefin-forming elimination (C).The results were compared with the behavior of the five- and six-membered rings.Reaction A shows negligible dependence on ring size.In contrast, reactions B and C are affected by ring size through ring strain and geometry of the transition state: the latter factor is held responsible for major differences in the reactivity profiles between such reactions.
